PHOTOELECTROCHEMICAL STUDIES OF COBALT-DOPED ZNO SPRAYED THIN-FILM SEMICONDUCTOR ELECTRODES IN ACETONITRILE MEDIUM

Photoelectrochemical properties of polycrystalline ZnO thin film electrodes doped with cobalt have been studied with particular emphasis on the extension of the photoresponse to the visible region. The film composition was found to differ from the composition of the spray solution. Films with a conductivity as high as 34 S cm-1 were obtained. The photocurrent-potential curves, absorption and action spectra of Co-doped ZnO electrodes indicated the significant extension to the visible region of its spectral response, confirming thereby the presence of Co2+ in tetrahedral sites of the ZnO lattice.